Our focussing system (or accommodation system), allows us to see clearly, especially up close. Our eyes are designed for distance vision, so when we look at something up close, the natural lens in our eye has to change shape to redirect light rays on the retina for near objects. It is the focussing system that allows you to keep things clear for reading up close. It also includes the ability to quickly shift focus when looking from near to far, such as when looking from our desk to the board.
For children with accommodation problems, print will become progressively blurry as they read for longer periods of time, and their eyes will fatigue from the strain of trying to keep the print clear. Sometimes children with focussing problems will hold their books very closely or lay their heads down. Headaches are a common symptom. Children with focussing problems may hold a book close or put their head almost on the desk to write. Reading glasses are often prescribed to help shore up inadequate focussing systems, but sometimes Vision Therapy is needed to improve a child’s focussing stamina. You can read more about Vision Therapy here